A Latin American perspective: the environmental impact of farming wheat and rice treated with carbofuran and Rhodamine B on Brazilian wild birds - Carbofuran and Wildlife Poisoning: Global Perspectives and Forensic Approaches - page 200

Figure 7.7 Throat dissection of a ruddy ground dove ( Columbina talpacoti ) showing the consumption
of treated wheat seeds that led to the bird's death. Note the presence of wheat seeds treated with
carbofuran and Rhodamine B (I), as well as seeds treated with carbofuran camouflaged with brown
dye (II). Birds that had ingested seeds from more than one of the treatments were excluded from
the analysis.
Photo taken by Álvaro Fernando de Almeida
mucus membranes. Such exposure is fatally toxic to eared dove (~120 g) and ruddy ground
dove (~40 g). This is similar to a finding made by M. Odino in Kenyan rice fields, as detailed
in Chapter 3.
The evident ingestion of red seeds (from the Rhodamine B coating) suggests that this colour is
not aversive to birds, which is in contradiction to the fi ndings of Avery and Mason (1997) and Nelms
and Avery (1997). The colour instead seems to attract at least certain species (Schmidt, Scheiefer and
Winkler 2004; Cuthill, Steves, Sheppard et al. 2005). The spectral quality of this colour is contrast-
ing and conspicuous to birds. This may explain why higher seed consumption occurred when seeds
were treated with carbofuran and Rhodamine B.
7.3.1 Alternatives and mitigation
During the eight days spent on experiment 4, comparisons were made between the effects of carbo-
furan and carbosulfan, using rice seeds dyed with Rhodamine B. In plots where seeds treated with
carbofuran were sown, 109 birds were found dead, and in those treated with carbosulfan, 40 were
recovered. These results differed signifi cantly (H 63.01; p 0.012; df 1; n 8). Greater
mortality was caused by carbofuran, suggesting that the use of carbosulfan may lessen the impact
of grain farming on wild birds. In turn, data clearly showed that carbosulfan use will still result in
notable mortality. Further, some birds were noted as having been visibly poisoned by carbosulfan,
yet managed to leave the test plot and (though disorientated) reach refuge outside the test area
(ca 550 metres away). We do not know if these poisoned birds recovered or died after escaping the
experimental plot.